1221011220101 has 8 divisors (see below), whose sum is σ = 1234317819384. Its totient is φ = 1207728491200.

The previous prime is 1221011220061. The next prime is 1221011220127. The reversal of 1221011220101 is 1010221101221.

It can be written as a sum of positive squares in 4 ways, for example, as 10450155076 + 1210561065025 = 102226^2 + 1100255^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1221011220101 - 2²⁶ = 1220944111237 is a prime.

It is a super-2 number, since 2×1221011220101² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221011220001) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5864726 + ... + 6069351.

It is an arithmetic number, because the mean of its divisors is an integer number (154289727423).

Almost surely, 2^{1221011220101} is an apocalyptic number.

It is an amenable number.

1221011220101 is a deficient number, since it is larger than the sum of its proper divisors (13306599283).

1221011220101 is a wasteful number, since it uses less digits than its factorization.

1221011220101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11935191.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 1221011220101 its reverse (1010221101221), we get a palindrome (2231232321322).

The spelling of 1221011220101 in words is "one trillion, two hundred twenty-one billion, eleven million, two hundred twenty thousand, one hundred one".